publishes Country Reports on Terrorism, which highlights current strategies, outcomes and casualties from U.S. counterterrorism efforts. The 2008 report highlights the growing trend in terrorist attacks abroad, including the September attack against the U.S. Embassy in Yemen that killed 18 people. The continued incidence of terrorism prompts us to consider its root causes. It is popular to sing...

We use elementary methods to prove an incidence theorem for points and spheres in Fq . As an application, we show that any point set P ⊂ Fq with |P | ≥ 5q determines a positive proportion of all circles. The latter result is an analogue of Beck’s Theorem for circles which is optimal up to multiplicative constants.

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A t-design rc with parameters t (u, k, A) is a finite incidence structure with u points and k points on each block such that any t-subset is contained in exactly 1 blocks. Incidence between a point P and a block d is denoted by P 1 d or d 1 P. We usually denote by b the number of blocks of 17. A block p of a t-design (t > 1) is said to be repeated x times if there exists exactly x blocks d such...

Given a regular action of a nite group G on a set V , we ask (and answer) the question of the existence of an incidence structure I = (V; B) on the set V whose full automorphism group Aut(I) is the group G in its regular action. Additional conditions on I also allow us to reene the original problem to the class of hypergraphs. Using results on graphical and digraphical regular representations (...

In this paper, we study when the incidence matrix of a symmetric (v, k, λ)-BIBD is a 3-frameproof code. We show the existence of infinite families of symmetric BIBDs that are 3-frameproof codes, as well as infinite families of symmetric BIBDs that are not 3-frameproof codes.

In this paper, we describe the use of graph-spectral techniques and their relationship to Riemannian geometry for the purposes of segmentation and grouping. We pose the problem of segmenting a set of tokens as that of partitioning the set of nodes in a graph whose edge weights are given by the geodesic distances between points in a manifold. To do this, we commence by explaining the relationshi...